US8614583B2 - Voltage detection circuit - Google Patents

Voltage detection circuit Download PDF

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Publication number
US8614583B2
US8614583B2 US12/970,963 US97096310A US8614583B2 US 8614583 B2 US8614583 B2 US 8614583B2 US 97096310 A US97096310 A US 97096310A US 8614583 B2 US8614583 B2 US 8614583B2
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United States
Prior art keywords
voltage
led
thyristor
anode
cathode
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Expired - Fee Related, expires
Application number
US12/970,963
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US20120139526A1 (en
Inventor
Yong-Zhao Huang
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hongfujin Precision Industry Shenzhen Co Ltd
Hon Hai Precision Industry Co Ltd
Original Assignee
Hongfujin Precision Industry Shenzhen Co Ltd
Hon Hai Precision Industry Co Ltd
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Application filed by Hongfujin Precision Industry Shenzhen Co Ltd, Hon Hai Precision Industry Co Ltd filed Critical Hongfujin Precision Industry Shenzhen Co Ltd
Assigned to HONG FU JIN PRECISION INDUSTRY (SHENZHEN) CO., LTD., HON HAI PRECISION INDUSTRY CO., LTD. reassignment HONG FU JIN PRECISION INDUSTRY (SHENZHEN) CO., LTD. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: HUANG, YONG-ZHAO
Publication of US20120139526A1 publication Critical patent/US20120139526A1/en
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Publication of US8614583B2 publication Critical patent/US8614583B2/en
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
    • G01R19/165—Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values
    • G01R19/16533—Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values characterised by the application
    • G01R19/16538—Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values characterised by the application in AC or DC supplies
    • G01R19/16542—Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values characterised by the application in AC or DC supplies for batteries
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
    • G01R19/165—Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values
    • G01R19/16504—Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values characterised by the components employed
    • G01R19/16523—Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values characterised by the components employed using diodes, e.g. Zener diodes

Definitions

  • the present disclosure relates to a voltage detection circuit.
  • the drawing is a circuit diagram of an embodiment of a voltage detection circuit.
  • a voltage detection circuit 100 is used to detect a voltage source VIN of an electronic device.
  • the voltage detecting circuit 100 includes a Zener diode VD, a thyristor SCR, a first light-emitting diode LED 1 (hereinafter first diode LED 1 ), a second light-emitting diode LED 2 (hereinafter second diode LED 2 ), and two resistors R 1 and R 2 .
  • a cathode of the Zener diode VD is connected to the voltage source VIN.
  • An anode of the Zener diode VD is connected to a control terminal of the thyristor SCR through the resistor R 1 .
  • An anode of the thyristor SCR is connected to an anode of the first diode LED 1 , and connected to the voltage source VIN through the resistor R 2 .
  • a cathode of the thyristor SCR is connected to a cathode of the first diode LED 1 and connected to an anode of the second diode LED 2 .
  • a cathode of the second diode LED 2 is grounded.
  • the first and second diodes LED 1 and LED 2 respectively emit different-colored light, and respectively have turn-on voltages V 1 and V 2 .
  • a breakdown voltage of the Zener diode VD is V VD .
  • the thyristor SCR is turned on, therefore the second diode LED 2 is turned on, and the first diode LED 1 is turned off. At this time, the first diode LED 1 does not light up, but the second diode LED 2 lights up, which means the voltage Vin of the voltage source VIN is greater than the maximum value of a required voltage range.
  • the first diode LED 1 When V 1 ⁇ Vin ⁇ V 1 +V 2 , the first diode LED 1 is turned on, the second diode LED 2 is turned off. At this time, the first diode LED 1 lights up and the second diode LED 2 does not light up, which means the voltage Vin of the voltage source VIN is less than the minimum value of the required voltage range but in a warning voltage range, therefore the electronic device may only work for a short time more.
  • the first diode LED 1 and the second diode LED 2 are both turned off. At this time, the first diode LED 1 and the second diode LED 2 don't light up, which shows the voltage Vin of the voltage source VIN is less than the minimum value of the warning voltage range, therefore the electronic device cannot work anymore.
  • the voltage detection circuit 100 can detect different voltage level of the voltage source VIN, which is very convenient.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Measurement Of Current Or Voltage (AREA)

Abstract

A voltage detection circuit used to detect a voltage source includes a Zener diode, a thyristor, a first resistor, a second resistor, a first light-emitting diode (LED), and a second LED. A cathode of the Zener diode is connected to the voltage source. An anode of the Zener diode is connected to a control terminal of the thyristor through a first resistor. An anode of the thyristor is connected to the voltage source through a second resistor. The anode of the thyristor is connected to an anode of the first LED. A cathode of the thyristor is connected to a cathode of the first LED. The cathode of the thyristor is connected to an anode of the second LED, and a cathode of the second LED is grounded.

Description

BACKGROUND
1. Technical Field
The present disclosure relates to a voltage detection circuit.
2. Description of Related Art
When a power supply unit, such as a battery of a computer motherboard, cannot supply enough voltage to the computer motherboard, the computer motherboard may not work normally. Therefore, a voltage detecting circuit for detecting voltage level is needed.
BRIEF DESCRIPTION OF THE DRAWING
Many aspects of the present embodiments can be better understood with reference to the following drawing. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present embodiments.
The drawing is a circuit diagram of an embodiment of a voltage detection circuit.
 DETAILED DESCRIPTION
The disclosure, including the accompanying drawing, is illustrated by way of example and not by way of limitation. It should be noted that references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references mean at least one.
Referring to the drawing, an embodiment of a voltage detection circuit 100 is used to detect a voltage source VIN of an electronic device. The voltage detecting circuit 100 includes a Zener diode VD, a thyristor SCR, a first light-emitting diode LED1 (hereinafter first diode LED1), a second light-emitting diode LED2 (hereinafter second diode LED2), and two resistors R1 and R2.
A cathode of the Zener diode VD is connected to the voltage source VIN. An anode of the Zener diode VD is connected to a control terminal of the thyristor SCR through the resistor R1. An anode of the thyristor SCR is connected to an anode of the first diode LED1, and connected to the voltage source VIN through the resistor R2. A cathode of the thyristor SCR is connected to a cathode of the first diode LED1 and connected to an anode of the second diode LED2. A cathode of the second diode LED2 is grounded. In one embodiment, the first and second diodes LED1 and LED2 respectively emit different-colored light, and respectively have turn-on voltages V1 and V2. A breakdown voltage of the Zener diode VD is VVD. In one embodiment, V1+V2<VVD.
In use, when the voltage Vin of the voltage source VIN is greater than the breakdown voltage VVD of the Zener diode VD, namely Vin>VVD, the thyristor SCR is turned on, therefore the second diode LED2 is turned on, and the first diode LED1 is turned off. At this time, the first diode LED1 does not light up, but the second diode LED2 lights up, which means the voltage Vin of the voltage source VIN is greater than the maximum value of a required voltage range.
When V1+V2<Vin<VVD, the thyristor SCR is turned off, therefore the first diode LED1 and the second diode LED2 are turned on. At this time, the first diode LED1 and the second diode LED2 both light up, which means the voltage Vin of the voltage source VIN is in the require voltage range.
When V1<Vin<V1+V2, the first diode LED1 is turned on, the second diode LED2 is turned off. At this time, the first diode LED1 lights up and the second diode LED2 does not light up, which means the voltage Vin of the voltage source VIN is less than the minimum value of the required voltage range but in a warning voltage range, therefore the electronic device may only work for a short time more.
When Vin<V1, the first diode LED1 and the second diode LED2 are both turned off. At this time, the first diode LED1 and the second diode LED2 don't light up, which shows the voltage Vin of the voltage source VIN is less than the minimum value of the warning voltage range, therefore the electronic device cannot work anymore.
According to the above working states of the first diode LED1 and the second diode LED2, the voltage detection circuit 100 can detect different voltage level of the voltage source VIN, which is very convenient.
It is to be understood, however, that even though numerous characteristics and advantages of the embodiments have been set forth in the foregoing description, together with details of the structure and function of the embodiments, the disclosure is illustrative only, and changes may be made in details, especially in matters of shape, size, and arrangement of parts within the principles of the embodiments to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.

Claims (3)

What is claimed is:
1. A voltage detection circuit to determine whether a voltage provided by a voltage source is within a required voltage range, the voltage detection circuit comprising:
a Zener diode comprising an anode and a cathode, wherein the cathode of the Zener diode is connected to the voltage source;
a thyristor comprising a control terminal, an anode, and a cathode;
a first resistor and a second resistor, wherein the anode of the Zener diode is connected to the control terminal of the thyristor through the first resistor, the anode of the thyristor is connected to the voltage source through the second resistor;
a first light-emitting diode (LED) comprising an anode and a cathode, wherein the anode of the thyristor is connected to the anode of the first LED, the cathode of the thyristor is connected to the cathode of the first LED; and
a second LED comprising an anode and a cathode, wherein the cathode of the thyristor is connected to the anode of the second LED, the cathode of the second LED is grounded;
wherein when the voltage of the voltage source is greater than a breakdown voltage of the Zener diode, the thyristor is turned on, the second LED is turned on, and the first LED is turned off, to indicate the voltage of the voltage source exceeds a maximum value of the required voltage range.
2. The voltage detection circuit of claim 1, wherein the first and second LEDs respectively emit different-colored light.
3. The voltage detection circuit of claim 1, wherein a breakdown voltage of the Zener diode is greater than a sum of turn-on voltages of the first and second LEDs;
wherein when the voltage of the voltage source is less than the breakdown voltage of the Zener diode, and greater than the sum of the turn-on voltages of the first and second LEDs, the thyristor is turned off, the first and second LEDs are turned on, to indicate the voltage of the voltage source is within the required voltage range;
wherein when the voltage of the voltage source is less than the sum of the turn-on voltages of the first and second LEDs, and greater than the turn-on voltage of the first LED, the thyristor is turned off, the first LED is turned on, and the second LED is turned off, to indicate the voltage of the voltage source is less than a minimum value of the required voltage range but in a warning voltage range; and
wherein when the voltage of the voltage source is less than the turn-on voltage of the first LED, the thyristor is turned off, the first and second LEDs are turned off, to indicate the voltage of the voltage source is below the warning voltage range.
US12/970,963 2010-06-12 2010-12-17 Voltage detection circuit Expired - Fee Related US8614583B2 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN201010574892.8 2010-06-12
CN201010574892.8A CN102486492B (en) 2010-12-06 2010-12-06 Voltage detection circuit

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US20120139526A1 US20120139526A1 (en) 2012-06-07
US8614583B2 true US8614583B2 (en) 2013-12-24

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10116129B1 (en) 2016-05-18 2018-10-30 Western Digital Technologies, Inc. EOS event detection circuit for detecting EOS event on supply voltage rail coupled to power supply

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103660951A (en) * 2012-09-05 2014-03-26 中国北车股份有限公司大连电力牵引研发中心 Voltage indication device of railway vehicle and railway vehicle
CN103018540B (en) * 2012-11-20 2015-07-01 山西省电力公司阳泉供电公司 Zero-sequence voltage detection device of 6-10 KV circuit
CN111585248B (en) * 2020-06-17 2022-03-18 西安国矽微半导体有限公司 Tripping circuit, method, control circuit and electric leakage detection system thereof

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US4558226A (en) * 1982-07-07 1985-12-10 Tokyo Shibaura Denki Kabushiki Kaisha Voltage detecting circuit with hysteresis characteristic and high noise immunity
US6121767A (en) * 1986-01-15 2000-09-19 Havel; Karel Digital multimeter with variable color range indication
US6275011B1 (en) * 1999-12-08 2001-08-14 Tai-Her Yang Charging device having a broad voltage changing range, automatic charging cutoff based on temperature detection, and charging status maintenance.
US6466029B2 (en) * 2000-04-04 2002-10-15 Contact Technology Systems, Inc. Power line testing device with signal generator and signal detector
US20050168162A1 (en) * 2004-02-02 2005-08-04 Pioneer Corporation Lighting device and lighting system
US20090021871A1 (en) * 2001-10-04 2009-01-22 Ise Corporation Energy Storage Pack Having Overvoltage Protection and Method of Protection
US20100123399A1 (en) * 2008-11-18 2010-05-20 Klaus Bollmann LED lighting system with bypass circuit for failed LED
US8415892B2 (en) * 2009-12-04 2013-04-09 Tai-Her Yang Voltage-limiting and reverse polarity series type LED device

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JP4581646B2 (en) * 2004-11-22 2010-11-17 パナソニック電工株式会社 Light emitting diode lighting device
CN201616684U (en) * 2009-11-27 2010-10-27 东营市海特电子有限公司 Charging circuit with automatic power-off function of charger

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4558226A (en) * 1982-07-07 1985-12-10 Tokyo Shibaura Denki Kabushiki Kaisha Voltage detecting circuit with hysteresis characteristic and high noise immunity
US6121767A (en) * 1986-01-15 2000-09-19 Havel; Karel Digital multimeter with variable color range indication
US6275011B1 (en) * 1999-12-08 2001-08-14 Tai-Her Yang Charging device having a broad voltage changing range, automatic charging cutoff based on temperature detection, and charging status maintenance.
US6466029B2 (en) * 2000-04-04 2002-10-15 Contact Technology Systems, Inc. Power line testing device with signal generator and signal detector
US20090021871A1 (en) * 2001-10-04 2009-01-22 Ise Corporation Energy Storage Pack Having Overvoltage Protection and Method of Protection
US20050168162A1 (en) * 2004-02-02 2005-08-04 Pioneer Corporation Lighting device and lighting system
US20100123399A1 (en) * 2008-11-18 2010-05-20 Klaus Bollmann LED lighting system with bypass circuit for failed LED
US8410705B2 (en) * 2008-11-18 2013-04-02 Ringdale, Inc. LED lighting system with bypass circuit for failed LED
US8415892B2 (en) * 2009-12-04 2013-04-09 Tai-Her Yang Voltage-limiting and reverse polarity series type LED device

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10116129B1 (en) 2016-05-18 2018-10-30 Western Digital Technologies, Inc. EOS event detection circuit for detecting EOS event on supply voltage rail coupled to power supply

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Publication number Publication date
CN102486492A (en) 2012-06-06
US20120139526A1 (en) 2012-06-07
CN102486492B (en) 2015-03-25

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